Three position switch and reset



Jan. 9, 1934. M. E. HENNlNG THREE POSITION SWITCH AND RESET I Filed Nov. 16, 1951 ezzzzzz'z A Q i/mw Patented Jan. 9, 1934 UNITED STATES PATENT OFFICE.

* THREE POSITION SWITCH AND RESET Malcolm E. n

enning, Des Molnes, Iowa, assignor to Penn Electric Switch 00., Des Molnes, Iowa,

a corporation of Iowa O ne object of my present invention is to provide a three position control device or switch and means for resetting the switch of simple, durable A further object is to provide in connection with a control device and an automatic power means therefor which moves the control device to inoperative position when conditions are other" than normal, a means for resetting the structure for automatic operation after the cause for moving the power means to other than normal posiation has been removed, such means being actuated merely by a single manual movement of a reset member after which the reset member is automatically returned to initial position for automatic operation of the power means- More particularly, it is my object to provide in connection with an automatically actuated -switch, which normally operates to temporary open and temporary closed positions and non- 80 normally operates to a manually operated reset means, which closes the switch after being non-normally but automatically actuated to its permanent open posi-, tion, such means being arranged to leave the switch in closed position even though the manually operated means is released until such time as automatic operation of the switch returns the manually operated means to its initial position because of the condition which caused it to move to permanent inoperative position having been til remedied and restores complete automatic operation of the switch structure. I

A further object is to provide in connection with a cam actuated control switch, which is con strained toward closed position, a means for resetting the switch after the cam has opened the switch and consisting of a manually movable device for moving the cam out oi normal engagement with the switch, so that the switch will return to closed position, resilient means being provided for automatically returning the cam to its initial position, but such return being prevented by engagement of the cam with the control switch, until such time as the closed position of the cam a permanent open position,

Serial No. 487,493,1l1ed October 9, 1930.;

- Application November 16,1981 9 Serial No. 575,277

20 Claims. (Cl. zoo-1:8}

is reached, whereupon automatic operation of the structure is resumed.

With these and other objects in view, m'rinvention consists in the construction, arrangement and combination of the various parts of my three position switch and reset, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawing, in which:

Figure 1 is a front elevation of a control structure embodying my invention, showing the cover plate removed therefrom.

Figure 2 is an enlarged, sectional view of the upper left-hand portion of Figure 1.

Figure 3 is a sectional view on the line 3-8 of Figure 1.

Figure 4 is a perspective view of a manually operable reset means; and

Figure 5 is a diagrammatic view showing my control structure used in connection with a stoker. 18 for a furnace.

In the accompanying drawing, I have used the reference numeral 10 to indicate a switch housing. A hub 12 extends therefrom for insertion through .a stack or chimney 16. Within the stack or chimney 16 a bimetallic coil 18 has one end secured at 20 to the hub 12 and its other end. secured to a rod 22. Thus temperature changes within the stack 16 will automatically impart r0- tation to the rod 22.-

The rod 22 rotatably extends through a bushing 24 and through a sleeve 26. The sleeve 20 is journaled in an opening 28 of the switch housing 10. A disc'30 and a pair of stop arms 32 are secured to the'sleeve 26 by a nut 34 to rotate with the sleeve. The stops 32 are adjustable relative to the disc 30 when the nut 34 is loosened for the purpose of changing the temperature adjustment, such'as disclosed in my co-pending application,

To impart rotation from the rod 22 to the sleeve 26, I provide a lever 86 secured to the rod 22 and movable'betw'een the stops 32, whereby a lost motion .connection is provided.

A cam sleeve 38 is slidably mounted on the sleeve ion 26 and rotation of one relative to the other is prevented by a pin 40 mounted in the sleeve 20 and projecting into a slot 42 of the cam sleeve 38.

The cam sleeve 38 is constrained to remain in the position shown in Figure 2 by a spring 44 con nected with the sleeves 26 and 38 respectively.

A control device .is provided in the form 01' a switch arm 46 pivoted on the pin 48 and carrying a contact 50, which is engageable with a stationary contact 52. A horseshoe magnet 54 acts 11 0 upon the switch arm 46 to constrain it toward closed circuit position. A resilient bell crank 56 is mounted on the pin 48 for imparting movement from the cam sleeve 38 to the switch arm 46.

One end of the bell crank 56 is curved as indicated at 56a and engages the periphery of a cam 58 formed on the cam sleeve 38. The cam 58 has a depression 60, which permits the contacts 50 and 52 to engage each other, because of the magnetic pull of the magnet 54 on the switch arm 46, whenever the depression registers with the end 56a of the bell crank 56.

I provide a reset member A in the form of a plate 62 having a finger engaging lip 64 and a cam engaging lip 66. The plate 62 is slidably mounted relative to the switch casing 10 by means of two screws 68 and a screw '70 extending through slots 72 and 74 respectively.

The reset member A is constrained to remain in its initial position shown by full lines in Figure 1 by reason of a spring 76, having one end engaging in a depression of the lip 66 and its other end anchored to a screw '18.

To prevent undesired rotation of the sleeve 26 and the cam 58, except when such rotation is imparted thereto by the lever 36 engaging one of the stops 32, I provide a friction washer 80.

A control device of the character described is especially desirable in connection with a stoker for a furnace. A furnace is indicated in Figure 5 at B. A fuel hopper is indicated at 82 from which fuel is conveyed through a tube 84 into the fire box of the furnace B. The conveyor is operated by an electric motor 86 which ordinarily also operates a blower to furnish air to the tire.

The switch contacts 50 and 52 are in series.with the motor, the motor wires being indicated at 88, 90 and 92. Other control devices, such as a room thermostat and a thermostat on the heating plant, are provided, but are not illustrated on the drawin lfy present control device is a safety switch which cuts out the motor 86, if the stack 16 becomes too hot and also breaks the circuit if it becomes too cold. If the stack temperature remains normal within certain limits the lever 36 will oscillate during cycles of operation of the stoker between the stops 32 without imparting any rotation to the sleeve 26 and the cam 58. This will allow the portion 56a of the bell crank 56 to remain in the depression 60, which may be considered the normal position. This position is indicated in Figure 3 and also the other positions of the device,-Figure 3 showing it in the too hot position.

When the device is in the too hot" position, the switch contacts will be broken as shown in Figure 1, by solid lines, but the switch will be operating automatically and normally, so that when the stack 16 cools down, normal position will again be reached and the contacts 50 and 52 will close to the dotted line position shown in Figure 1, so that the motor 86 will again be energized if the room thermostat and other controls require it. In some instances, however, such as on a mild day when the room thermostat does not call for heat, except after a long period of time, the fire might have gone out or ignition or fuel failure may occur, so that the stack 16 will become too cold." and the contacts 50 and 52 will be separated. It is then necessary to overcome whatever difllculty caused movement of the switch to too cold" position and reset the devieefor automatic operation.

Resetting-is accomplished by manually moving the reset member A to the dotted line position shown in Figure 1, whereupon the magnet 54 will close the switch. When the reset member A is released, the spring 76 returns it to its initial position and the spring 44 tends to return the cam 58'to its normal position. The end 56a of the bell crank 56, however, offers an obstruction to such return of the cam and the side of the cam will remain in contact with the end of the lever 56a.

Thereafter as the stack 16 heats up, it will move the cam 58 until normal position is reached, whereupon the depression 60 will be in registry with the lever 56 and the spring 44 can then pull the cam to its initial position.

It is obvious that thereafter operation of the entire device is resumed and will continue until a too cold position is again caused by failure of heat in the stack 16.

By this particular arrangement of resetting mechanism, the reset member A does not have to be held manually in the dotted position of Figure 1 until the stack 16 has heated sufficiently to cause registry of the notch 60 with the lever 56 but can be released as soon as it has been actuated.

Automatic operation of the entire device is then resumed, providing the stack 16 heats up in the proper manner.

Some changes may be made in the construction and arrangement of the various parts of my three position switch and reset, without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of. structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a structure of the class described, circuit control means for making and breaking an electric circuit, a single means responsive to different degrees of a single condition to normally automatically operating said circuit control means dependent on normally opposite conditions for making and breaking said electric circuit, said condition responsive means also serving to break said circuit upon operation of the condition responsive means when responsive to an other than normal extreme of one of said opposite conditions and manually operable means for actuating said circuit control means to make said circuit after the same has been broken on account of said other than normal actuation and for thereby resetting said circuit control means to assume a position for automatic actuation after the other than normal cause of actuation has been removed.

2. In a structure of the class described, a control device, a temperature responsive element for automatically and progressively actuating said control device to temporary inoperative, temporary operative and permanent inoperative positions during movement of said element in one direction and manually operated means for moving said control device to operative position after being actuated to its permanent inoperative position to thereby permit the resetting of the structure for automatic operation after the cause for assuming said permanent inoperative position has been remedied.

3. In a structure of the class described, a control device, means constraining said control device to operative position, said control device being movable to inoperative position, a temperature responsive element movable to an operating normal automatic position permitting said control device to assume operative position because of the action of said means and to move it to its inoperative position when the temperature responsive element is in non-operating position because of non-normal operating conditionsoccurring and means to restore said structure to position for normal automatic operation, said last means adjusting a portion of said temperature responsive element to position for permitting said control device to assume operative position and said temperature responsive element and control device then cooperating with each other to prevent actuation of the control device to inoperative position until the temperature responsive element has moved to position for resumption of normal automatic operation because of the cause for movement of the temperature responsive element to non-operating position having been remedied.

4. In a structure of the class described, a control device movable to operative and inoperative positions, means constraining said control device toward operative position, a rod automatically rotatable, a cam thereon rotatable therewith and slidable relative thereto, said cam engaging said control device to move it to its operative and inoperative positions, manually operable means to slide said cam relative to said rod to permit said first means to move said control device to operative position after being moved to inoperative position by said cam, means to return said cam to its initial position upon the part thereof which normally moves said control device to operative position registering with the control device, whereupon automatic operation of the structure is resumed.

5. Ina structure of the class described, a control device movable to operative and inoperative positions, means constraining said control device toward operative position, a rod automatically rotatable, a cam thereon rotatable therewith and slidable relative thereto, said cam engaging said control" device to move it to its operative and inoperative positions, manually operable means to slidesaid cam relative to said rod to permit said first means 'to move said control device to operative position after being moved to inoperative position by said cam, andv resilient means restraining said cam to return to its initial position, said cam engaging said control device to prevent such return except upon movement of the cam to position for movement of the control device to operative position whereupon automatic operationof the structure is restored.

6. In a structure of the class described, a con trol device movable to operative and inoperative positions, a rod automatically rotatable, an actuator slidable on said rod and actuatingly engageable with said control device for moving it to its two positions upon rotation 0! said rod, and manual operating means for imparting sliding movement to said actuator to move said control device to operative position after being moved to inoperative position by said actuator, said control device engaging said actuator to prevent its return to actuatingly engageable position, except when said actuator is rotated to position for normal movement of the control device to operative position.

'1. In a structure of the class described a control devicemovable to operative and inoperative positions, means constraining said control device toward operative position, a rod automatically rotatable, a cam thereon rotatable therewith and slidable relative thereto, said cam engaging said control device to move it to its operative and inope tive positions, and manually operable means to de said cam relative to said rod to permit said first means to move said control device to operative position after being moved to inoperative position by said earn.

8. In a structure of the class disclosed, a control device movable to operative and inoperative positions, automatic power means for moving said control device to operative position under normal operating conditions and to inoperative position under other than normal operating conditions and manually operable means to render said power means inefiective to retain the control device in inoperative position, said power means cooperating with said control device to prevent the power means from moving the control device to inoperative position after the manually operable means ,is released until the power means has been automatically moved to position for normal automatic movement of the control device to operative position.

. 9. In a device or the class described, an actuating mechanism, a cam operable therefrom, a control mechanism normally coacting with and operable by said cam, said cam being non-normally movable relative to said actuating mechanism to a non-coacting position relative to said control mechanism for re-set purposes,

10. In a device of the class described, an actuating mechanism, a cam operable therefrom, a control mechanism normally coacting with 'and operable by said cam, said cam being non-normally movable relative to said actuating mechanism to a non-coacting position relative to said control mechanism and means to constrain said cam to return to normal coacting position relative to said control mechanism.

11. In a device of the class described, an actuating mechanism, a cam operable therefrom, a control mechanism normally coacting with and operable by said cam, manually movable mechanism for moving said cam relative to said actuating mechanism to non-coacting position relative to said control mechanism and resilient means constraining said cam to return to normal coacting position upon release of said manually movable mechanism.

12. In a device of the class described, an actuating mechanism, a cam operable therefrom, a control mechanism arranged for normal and nonnormal coaction with said cam, said cam being manually movable relative to said actuating mechanism to non-coacting position relative to said control mechanism and means to return said cam to non-normal coaction with said control mechanism and maintain said cam and said control mechanism in such position until the actuating mechanism moves the cam to a position for resumption of normal cd'action of the. cam and control mechanism.

13. In a structure of the class described, means for making and breaking an electric circuit, power means for normally automatically actuating said first means to circuit making and circuit breaking positions,'said power means also serving to actuate said first means automatically to another circuit breaking position upon nonnormal operating conditions and manually operated means for moving said first means to circuit making position aiter being actuated to its second mentioned circuit breaking position and for thereby rendering said first means operative to make said circuit under non-normal operating conditions until the structure assumes position first means to circuit making position alter be- I ing actuated to its second mentioned circuit breaking position and for thereby rendering said J first means operative to make said circuit under non-normal operating conditions until the structure assumes position for normal operation whereaiter normal automatic actuation is permitted.

15. In a structure of the class described, means for making and breaking an electric circuit, power means for normally automatically actuating said first means to circuit making and circuit breaking positions, said power means also serving to actuate said first means automatically to another circuit breaking position upon nonnormal operating conditions, manually operated means for moving said first means to circuit making position after being actuated to its second mentioned circuit breaking position and for thereby rendering said first means operative to make said circuit under non-normal operating conditions until the structure assumes position for normal operation and means for then re turning said manual means to its initial position.

16. For use with an electrically operated iuel burner, a switch structure comprising meansior making and breaking an electric circuit thereto, power means for normally automatically actuating said first means to inoperative and. operative positions, said power means also serving to actuate said first means automatically to another inoperative position upon non-normal operating conditions and manually operated means for moving said first means to operative position after being actuated to its second mentioned inoperative position and for thereby rendering said first means operative under nonnormal operating conditions until the structure assumes position for normal operation whereaiter normal automatic. actuation is permitted.

1?. In an automatic control structure, means for making and breaking an electric circuit, a single automatic means responsive to different degrees of a single condition operatively connected with said first means for normally moving it to temporary circuit breaking and temporary circuit making positions and for nonmeans is released until the power to position for subsequent automatic operation oi the first means.

18. In a structure of the class described, means for making and breaking an electric circuit movable to operative and inoperative positions, a single automatic power means responsive to dilterent degrees of a single condition for moving said first means to operative position under normal operating conditions and to inoperative position under other than normal operating conditions and manually operable means to render said power means inefiective to retain the first means in inoperative position, said power means cooperating with said first means to prevent the power means from moving the first means to operative position after the manually operable means has been automatically moved to position for normal automatic movement 01' the first means to operative position.

19. A control structure for use with an electrically operated fuel burner, comprising, means for making and breaking an electric circuit, temperature responsive means for operating said means for making and breaking an electric circuit under normal operating condition oi the fuel burner, said temperature responsive means likewise operable under non-normal condition of the fuel burner to break the electric circuit structure for normal operating condition oi the fuel burner while the fuel burner remains in non-normal operating condition and for permitting resumption of the normal operating condition thereof.

20. In a structure of the class described, circult control means for making and breaking an electric'circuit and means responsive to condi-- tions caused from a single source for normally automatically operating said circuit control means dependent on normally opposite conditions for making and breaking said electric circuit, said condition responsive means also serving to break said circuit upon operation oi the condition responsive means when responsive to an other than normal extreme of one of said opposite conditions.

' MALCOLM E. HENN'ING. 

